In motion chairs which have an operating mechanism which includes side linkages that have respective pantograph (lazy-tong) linkage systems for thrusting and raising an ottoman (sometimes called a legrest or a footrest), when the mechanism is operated in one sense, and for lowering and stowing that ottoman when the mechanism is operated in an opposite sense, it is customary to mount the ottoman (which generally is a frontally upholstered and padded fairly rigid board), by bolting the ottoman directly to links, flanges or brackets which form corresponding forward ends of the respective pantograph linkage systems (including parallelogram linkage extensions which may be provided as parts of such linkage systems).
Recently, with gains in widespread usage of motion chairs and with improvements in reporting of incidents, the manufacturers of motion chairs have become aware of the desirability of further minimising risks due to uninformed, unintended and, particularly, small children's incorrect use of such furniture.
One measure which recently has gained acceptance is the substantial filling of the space between the ottoman and the front of the seat cushion of the chair, by an apron of upholstery material hanging in a catenary between these two places, or by a sub-ottoman (sometimes called a supplemental or secondary ottoman), which is mounted between respective intermediate links of the pantographs of the two side linkages. It is thought that if no space wide enough to permit a child's head to be inserted between the sub-ottoman and both the main ottoman and the front edge of the seat cushion is present, when the ottoman is in its extended condition and when the ottoman is being moved to and from its extended condition, it has become practically unlikely that a child or pet will become entrapped to their detriment, in that space.
In recent months, consumer and retailer interest has been sparked in electrically-operated motion chairs. Although the mechanical designs for such chairs, basically have been available for many years, and heretofore have found a limited market in the manufacture of dentist's chairs, invalid's chairs and the like, for reasons not easily understood, it seems that electrically-operated motion chairs, including recliners and other motion chairs having thrustable/retractile ottomans may be on the verge of widespread and protracted popularity.
Accordingly, it is useful at this stage for a manufacturer of such chairs not simply to retrieve a classical special-purpose electrically-operated chair mechanical design and lightly adapt it for consumer use, nor simply to electrify an existing manually-operated motion chair design, without also reviewing whether the mechanical design for an electrically-operated motion chair can be improved so as to lower the risks of its improper use. It is also appropriate, in such a case, to consider further whether any feature added to an electrically-operated motion chair could prove beneficial if also provided on manually-operated motion chairs, whether in order also to lower risks due to improper use, or to improve versatility of use, or simply to limit the diversity of different mechanisms which a manufacturer must keep in stock in order to make different types of motion chairs.
The present inventor is aware that others faced with the same design challenges, and working at the behest of other motion chair manufacturers or motion chair hardware manufacturers recently have devised ways and means for permitting an ottoman to become detached from the side linkages should a certain amount of resistance be encountered by the ottoman as the ottoman is being retracted towards a fully stowed condition. (Besides addressing the lodging issue, such a feature also addresses the problem, possibly present with poorly designed or manufactured electrically-operated motion chairs, of how to prevent damage to the ottoman if the electric motor that is effecting the closure is not turned-off at the point where full retraction and stowage of the ottoman has been achieved.) However, it appears to the present inventor that complete popping-off of the ottoman under such conditions, e.g. where the ottoman is secured by pop-type fasteners or by Velcro strips, may not always be a fully satisfactory mode of providing the desired functioning. Especially when the ottoman also is attached to the front of the upholstered chair using a drape of upholstery cloth, the unnoticed detachment of the ottoman from its mountings can, in the next operation of the chair, easily lead to ripping of the drape of upholstery cloth. And Velcro strips can become so fouled that they will no longer hold, due to catching dust, carpet fuzz, fabric ravelings and the likes, instead of one another.
The present invention arose in the context of rethinking an electrically-operated motion chair mechanical design, in which the lodging issue is addressed in a manner which seems not only to be more fully satisfactory, but also to be applicable to many mechanical designs of manually-operated motion chairs.
In my aforementioned copending U.S. patent application Ser. No. 857,323, I have disclosed a resiliently releasing ottoman for use on a motion chair in which the front end of each side linkage of an ottoman thrusting/retracting pantograph linkage system for the motion chair is provided by a link, pivotally mounted to respective front end links at two vertically spaced sites. For each side, an ottoman mounting bracket is provided, having a generally vertical-plane flange and a transverse flange. The ottoman is secured to the two transverse flanges, and the vertical-plane flange, which extends below the transverse flange, is pivotally secured near its lower end to a corresponding lower end site on the pantograph front end links. The vertical-plane flanges of the ottoman-mounting brackets lie outboard of and in planes parallel to those of the respective front end links. A tension coil spring is provided at each side for tending to keep the ottoman positioned across the front edges of the front end links. But if, while the mechanism is being operated in a closing sense, the upper, rear edge of the ottoman encounters unusual resistance typical of someone or something being in the space through which the ottoman must move to fully retract, the ottoman will tiltingly release, against tensioning of the springs, permitting whatever is lodged, especially if it is animate, the opportunity and facility to escape, whereupon the springs will restore the ottoman to its normal disposition. By preference a stop is provided to limit tilting of the ottoman to about 90 degrees, in order to avoid damage to the springs which could occur were the ottoman to be intentionally tilted by a chair user's feet, e.g. so the user, while having the ottoman extended, could rest his or her feet against what, normally, is the backside of the ottoman.